The present invention relates to a mechanism suitable for locking a bolt or a nut.
Generally a bolt or a nut are locked by an elastic locking method using a spring washer or an adhesive locking method using an adhesive. The elastic locking method fastens members to be fastened together by twisting a bolt into a nut with a washer interposed between the bolt or the nut and the member. If the members are fastened together with the bolt and the nut without using any spring washer, there are presented some inconveniences that when the bolt and the nut suffer heat and vibrations so that the members are disfigured, or when the bolt and the nut become loose for forming a gap therebetween, the fastening effect of the bolt and the nut become ineffective. The spring washer is used to avoid such ineffectiveness of the fastening effect of the bolt and the nut. However, even the use of spring washer is unable to prevent perfectly the bolt and the nut from loosening due to the action of heat and vibrations on the bolt and the nut. Meanwhile, the adhesive locking method filters an adhesive into gaps between the openings of the bolt and the nut to lock together the bolt and the nut fastening members to be fastened together from loosening. If the adhesive is heated to a high temperature not lower than 100xc2x0 C., the adhesive may possibly melt and the locking effect of the adhesive may become ineffective. The adhesive may possibly be softened if the adhesive is heated at a temperature exceeding 50xc2x0 C. and the bolt and the nut may possibly be made to become loose by vibrations.
As indicated in FIGS. 20A and 20B, When a bolt 21 and a nut 22 are used under a severe condition in which the bolt and the nut suffer both heat and vibrations, a through hole 23 is formed through the nut 22 and the bolt 21 after fastening members to be fastened together with the bolt 21 and the nut 22, and a spring pin 24 or a split cotter pin 25 is inserted in the hole 23 formed through the nut 22 and the bolt 21 to locking the nut to the bolt.
When the members to be fastened together are made of soft material, such as aluminum or a plastic material, touching portions of the members in contact with the nut and the head of the bolt may cause plastic deformation due to compressive force exerted thereon by the bolt and the nut and vibrations, so that gaps can be formed therebetween. Therefore, periodical inspection is necessary. Upon such inspection, the split pin or the spring pin must be removed and the nut or the bolt must be refastened. Then another through hole must be formed through the nut and the bolt and the split pin or the spring pin must be inserted in the new through hole for locking.
If the through hole is formed every time the deformation of the members is inspected, many through holes are formed through the bolt, so that the strength of the bolt decreases necessarily. The strength of the bolt consequently decreases to a level not high enough to exert a sufficient compressive force to the members. Therefore, the bolt must sometimes be replaced with a new one.
Since, the work for locking the nut to the bolt, in most cases, is carried out after completing the fabrication of the members to be fastened together, chips produced when the through hole is formed through the nut and the bolt, are occasionally scattered in the peripheral equipment. In some cases, such chips cause a electrical trouble in the peripheral equipment. In some cases, it is difficult to form a through hole or insert the split pin or the spring pin in new through hole because of a position of the nut and the bolt.
It is an object of the present invention to provide a bolt and a nut locking mechanism capable of readily fastening members to be fastened together with at least one of a bolt and a nut and of preventing at least one of the bolt and the nut from becoming loose.
To achieve the above mentioned object, the present invention provides the following bolt or nut locking mechanism.
A bolt locking mechanism according to the present invention, in which a bolt is locked by using a taper piece and a plate member, such as a washer, comprises the bolt for fastening at least two members together, which has a head and a shaft and one of the head and shaft is provided with a first part in the side, the plate member for putting between the bolt and one of the members, which has a second part on one face to be contacted with the bolt and a third part on another face and a first hole for passing the bolt through, and the taper piece for embedding in the one of the members, which has a portion provided with a fourth part on a face to be contacted with the another face of the washer and a second hole for passing the bolt through. When the bolt fastens the members trough the washer and the taper piece, the first part and second part engage with each other and the third part and the forth part engage with each other for preventing the bolt from loosening, respectively. Accordingly, the bolt locking mechanism prevents the bolt from rotating in an loosening direction relative to the member.
A locking mechanism according to the present invention, in which one of a bolt and a nut is locked by using a taper piece, comprises a bolt and a nut for fastening at least two members together, one of which has a first part, a taper piece for embedding in one of the members, which has a portion provided with a second part on a face to contact with one of the bolt and the nut and a hole for passing the bolt through. The first part and the second part engage with each other for preventing one of the bolt and the nut from loosening when the bolt and the nut fasten the members through the taper piece. Accordingly, the locking mechanism prevents one of the bolt and the nut from rotating in an loosening direction.
A nut locking mechanism according to the present invention, in which a nut is locked by using a taper piece and a plate member, such as a washer, comprises a bolt and the nut, which is provided with a first part in the side, for fastening at least two members together between the bolt and the nut, the plate member for putting between the nut and one of the members, which has a second part on one face to contact with the nut and a third part on another face and a first hole for passing the bolt through and the taper piece for embedding in the one of the members, which has a portion provided with a fourth part on a face to contact with the another face of the washer and a second hole for passing the bolt through. When the bolt and the nut fasten the members through the washer and the taper piece, the first part and second part engage with each other and the third part and the forth part engage with each other for preventing the nut from loosening, respectively. Accordingly, the nut locking mechanism prevents the nut from rotating in an loosening direction relative to the member.